Electronic properties of the crystalline phases of theSb2S3−Tl2Ssystem

Autor: S. Dupont, Pierre-Emmanuel Lippens, Jean-Claude Jumas, C. Sénémaud, Josette Olivier-Fourcade, A. Gheorghiu
Rok vydání: 1997
Předmět:
Zdroj: Physical Review B. 56:13054-13065
ISSN: 1095-3795
0163-1829
Popis: The electronic properties of the crystalline phases of the ${\mathrm{Sb}}_{2}{\mathrm{S}}_{3}{\ensuremath{-}\mathrm{T}\mathrm{l}}_{2}\mathrm{S}$ system are investigated both experimentally and theoretically. Experimental data obtained by x-ray photoelectron spectroscopy and ${}^{121}\mathrm{Sb}$ M\"ossbauer spectroscopy are reported and analyzed from tight-binding calculations, which are used here because of the complexity of the materials. The main features of the x-ray photoelectron valence bands and S $K\ensuremath{\beta}$ emission spectra are identified. The binding energy of the S ${2p}_{3/2}$ core level is found to decrease from ${\mathrm{Sb}}_{2}{\mathrm{S}}_{3}$ to ${\mathrm{Tl}}_{2}\mathrm{S}$ in agreement with the variations of the calculated S charges. We show that the ${}^{121}\mathrm{Sb}$ M\"ossbauer isomer shift and the surface of the prepeak observed in x-ray-absorption spectra at the Sb ${L}_{\mathrm{III}}$ edge can be linearly correlated because they are both strongly dependent on the Sb $5s$ electron population. Finally, analytical expressions of the numbers of Sb and S valence electrons are derived from simple molecular calculations. These expressions provide rather simple explanations for the observed main trends in the variations of the experimental results in terms of local structural changes.
Databáze: OpenAIRE